GHK Cu Peptide Before and After Results The Effect of the Human Peptide GHK on Gene Expression Relevant to Nervous System Function and Cognitive Decline Ghkcu Peptide Cream Vs Injectable TikTok Essential GHK Cu Serum: What It Is, How It Works, and Why It Matters f Bacteriostaticwater.com A GHK Cu face serum appears blue because the active ingredient, GHK Cu ( copper peptide), is naturally a blue colored powder, meaning its inherent color transfers to the serum when mixed in; this blue hue